Air Compressor

ABSTRACT

A compact lightweight air compressor is provided with a DC motor to provide versatile use in the field where no AC power source is available. The air compressor includes a intercooler storage vessel for cooling and storing the compressed air as well as a cooling fan arrangement that allows cooling of all the air compressor components.

FIELD

The present disclosure relates to air compressors and more particularly, to a portable air compressor having a compact and lightweight design.

BACKGROUND

The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.

Air compressors have been found to be useful for numerous tasks including inflating tires and rafts, providing compressed air to power tools such as power nailers, impact wrenches, ratchets and other uses. The availability of compressed air sources is generally limited, based upon the common necessity for an AC power source. Furthermore, the size and weight of typical air compressors can prohibit the use of air compressors in certain instances.

SUMMARY

A portable air compressor is provided including a compact lightweight construction which is provided with a DC electric motor that allows the compressor to be driven by a vehicle battery or other DC power sources. The air compressor can include a crank assembly connected to a first end of the drive shaft of the electric motor. A connecting rod can be attached to the crank assembly. A piston is connected to the connecting rod. A cylinder assembly is fixedly mounted relative to a first end of the electric motor and receives the piston therein. A fan can be drivingly attached to a second end of the drive shaft and a shroud can surround the fan for directing cooling air axially along the motor housing from the second end towards the first end. An intercooler assembly is connected to the cylinder assembly for receiving compressed air from the cylinder assembly.

Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

DRAWINGS

The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.

FIG. 1 is a perspective view of an air compressor according to the principles of the present disclosure;

FIG. 2 is a perspective view of the air compressor shown in FIG. 1 with the optional handle removed;

FIG. 3 is a partially exploded perspective view of the motor/compressor assembly and fan assembly according to the principles of the present disclosure;

FIG. 4 is an end view of the motor/compressor assembly according to the principles of the present disclosure;

FIG. 5 is a perspective view of the crank case according to the principles of the present disclosure;

FIG. 6 is an exploded perspective view of the crank case connecting rods and piston assemblies according to the principles of the present disclosure;

FIG. 7 is a perspective view showing the assembly of the connecting rods and pistons to the crank case and electric motor according to the principles of the present disclosure;

FIG. 8 is a partial cross-sectional view of the assembly shown in FIG. 7;

FIG. 9 is a partially exploded perspective view of the cylinder assemblies being mounted to the crank case according to the principles of the present disclosure;

FIG. 10 is a perspective view of the base of the compressor according to the principles of the present disclosure;

FIG. 11 is a perspective view illustrating the mounting of the solenoid to the base according to the principles of the present disclosure;

FIG. 12 is a perspective view illustrating the mounting of the compressor and the electric motor assembly into the base according to the principles of the present disclosure;

FIG. 13 is a top plan view of the electric motor and compressor mounted within the base according to the principles of the present disclosure;

FIG. 14 is a perspective view illustrating the assembly of the intercooler assembly onto the compressor unit according to the principles of the present disclosure;

FIG. 15 is an exploded perspective view illustrating the assembly of the handle assembly to the compressor according to the principles of the present disclosure; and

FIG. 16 is a schematic diagram of the control circuit for the air compressor according to the principles of the present disclosure.

DETAILED DESCRIPTION

The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.

With reference to the attached Figures, the air compressor 10 will now be described. The air compressor 10 can include a base 12, an electric motor and compressor assembly 14, a compressed air storage vessel 16 and an optional handle assembly 18.

With reference to FIG. 3, the motor and compressor assembly 14 will now be described. The motor and compressor assembly 14 includes an electric motor 20 that can be a DC powered series wound field motor. The electric motor 20 includes a drive shaft 22 (best shown in FIG. 8) that can be accessible from both ends of the electric motor 20. A crank case 24 is mounted to a first end of the electric motor 20. As shown in FIG. 5, the crank case 24 includes a radially extending bearing support wall 26 which is disposed against the electric motor 20 in the assembled position. The bearing support wall 26 supports a bearing assembly 28 for receiving and supporting the drive shaft 22 of the electric motor therein. The crank case 24 includes a pair of legs 30 that include a threaded bore therein for mounting the crank case 24 to the base 12.

The crank case 24 includes at least one and optionally two cylinder mounting flanges 34 for mounting the cylinder assemblies 36 thereto as illustrated in FIG. 4. The cylinder mounting flanges 34 can include a plurality of threaded apertures 38 for receiving fasteners for mounting the cylinder assemblies 36 thereto. In addition, a pair of apertures 40 can be provided for receiving dowel pins 42 for precisely locating the cylinder assemblies 36 relative to the crank case 24. The crank case 24 includes apertures 44 provided in each of the cylinder mounting flanges 34 for receiving a connecting rod 46 therein. The connecting rods 46 are mounted to a crank assembly 48 which is drivingly connected to the drive shaft 22, as best illustrated in FIGS. 6-8.

The crank assembly 48 can include a counterweight member 50 having an aperture 52 with a pair of flats 54 for receiving the drive shaft 22 of the electric motor 20. The counterweight member 50 includes a slot 56 extending from the aperture 52 to a perimeter surface of the counterweight member 50. A fastener 58 is provided in an aperture 60 that traverses the slot 56 so as to allow the counterweight member 50 to be clamped onto the driveshaft 22 by tightening the fastener 58 and drawing the slot 56 closed. An offset crank pin 64 is connected to the counterweight member 50 and is received in the connecting rods 46. A pair of spacers 65 are provided between the connecting rods 46 and a rotor clip 66 secures the connecting rods 46 on the crank pin 64.

As shown in FIG. 6, a piston assembly 68 is mounted to the connecting rod 46 for receipt in the cylinder assembly 36. The present disclosure provides an exemplary compressor device that includes a V-twin (two) piston-cylinder arrangement, although it should be understood that a single piston air compressor is also contemplated as being within the scope of the present disclosure. Furthermore, the addition of further cylinders could also be utilized within the scope of the present disclosure. With reference to FIG. 9, the cylinder assemblies 36 can include a cylinder body 70 that can include exterior cooling fins 72. A first cylinder gasket 74 is disposed on the cylinder mounting flange 34 and the cylinder body 70 includes apertures 76 for receiving the dowel pins 42 for properly locating the cylinder body 70 on the cylinder mounting flange 34. A second cylinder gasket 80 is provided on the upper end of the cylinder body 70 and a valve plate assembly 82 is disposed above the second cylinder gasket 80. A head gasket 84 is provided above the valve plate assembly 82 and a head 86 is provided above the head gasket 84. The head 86 includes a plurality of mounting apertures 88 for receiving threaded fasteners 90 therethrough that extend through corresponding apertures in the head gasket 84, valve plate assembly 82, second cylinder gasket 80, cylinder body 70, first cylinder gasket 74 and are threadedly engaged with threaded apertures 38 provided in the cylinder flange 34 of the crank case 24.

With reference to FIG. 4, the head 86 of the cylinder assembly 36 can include an inlet fitting in the form of an elbow 92 providing suction air to the cylinder assembly 36. A filter 94 can be attached to the fitting 92 for preventing dust and debris from entering the compressor. A discharge fitting in the form of an elbow 96 is provided in communication with an exhaust passage of the cylinder assembly 36. As shown in FIG. 14, the discharge fittings 96 are connected to elongated copper tubes 98 which extend a length of the compressed air storage vessel 16 and are connected to inlet fittings 100 provided on the opposite end of the compressed air storage vessel 16. The elongated copper tube 98 provides a cooling function for the compressed air being discharged from the cylinder assemblies 36 prior to introduction into the compressed air storage vessel 16. The tubing 98 can be made from copper, but can also be made from additional materials that may exhibit good heat conduction properties.

The compressed air storage vessel 16 can be in the form of an intercooler which provides a storage vessel combined with a plurality of cooling fins to assist in cooling the compressed air received in the storage vessel 16. The vessel body can be formed by extrusion or casting with the end walls being webbed to the finned body. The storage vessel 16 can be provided with an outlet fitting 104 which serves as a quick connect for connection to various air hose and accessories which are known in the air compressor art. The intercooler 16 can also be provided with a pressure relief valve 106 and a pressure switch as will be described in greater detail herein.

With reference to FIG. 3, a fan 110 is mounted to a second end of the electric motor 20. A spacer 112 can be provided between an end of the drive shaft 22 and the fan 110. A fastener 114 can be inserted through an aperture 116 in the fan 110 and an aperture 118 in the spacer 112 to threadedly engage a threaded aperture 120 provided in the end of the drive shaft 22. An additional bushing 122 and spring lock washer 124 can be utilized for securing the fan 110 to the drive shaft 22. A shroud 128 can include an annular wall portion 130 that can surround the fan 110 to direct air flow from the fan 110 in an axial direction along the surface of the motor 20 toward the cylinder assemblies 36 and also along a bottom surface of the intercooler storage vessel 16. The shroud 128 includes a inlet aperture 132 that allows air to be drawn into the shroud 128 and then to be expelled axially along the motor.

With reference to FIG. 4, it is noted that an end cap 136 can be mounted to the open end of the crank case 24. The end cap can be mounted to the crank case 24 by a plurality of fasteners 138 which engage threaded apertures 140 provided in the open end of the crank case 24, as best illustrated in FIG. 9.

With reference to FIGS. 10 and 11, the base 12 can include a base wall 144 and a plurality of side walls 146 a-c. The side walls 146 a-c can be provided with vent holes 150 for allowing cooling air to pass into the base for cooling the motor and compressor assembly 14 as well as cooling the compressed air storage vessel 16 and the compressor electronics. The vent holes 150 can be arranged to provide for sufficient cooling air to enter the base 12 for cooling the air compressor components. The base 12 includes a mounting aperture 160 for mounting a switch solenoid device 154. The use of threaded fasteners 156 and threaded nuts 158 are one exemplary method of mounting the solenoid 154, although other methods of mounting the solenoid 154 can be utilized. The switch rocker 152 is inserted through an opening 160 provided in sidewall 146 c.

With reference to FIG. 12, the motor and compressor assembly 14 can be inserted into the base 12 and secured to the bottom wall 144 by threaded fasteners 162 and nuts 164. The bottom wall 144 is provided with apertures 166 for receiving the threaded fasteners 162. In the assembled condition, the fan shroud 128 can be opposite to the side wall 146 c which can be provided with vent holes 150 to allow sufficient air flow to be drawn into the fan 110 for cooling the components of the air compressor. As illustrated in FIG. 13, the shroud 128 is disposed near the solenoid 154 so that air being drawn into the shroud 128 passes over the solenoid 154 to cool the electronic components. The fan 110 then directs the air axially along the surface of the motor 20 for further cooling of the motor 20 and compressor components.

With reference to FIG. 5, the crank case 24 includes mounting bosses 170 each provided with threaded apertures 172. As illustrated in FIG. 14, a pair of elongated fasteners 174 are provided for insertion through mounting apertures 176 provided in the end side wall 146 c and insertion through apertures or slots 180 provided in the compressed air storage vessel 16 and then are threadedly received in the bosses 170 for securing the compressed air storage vessel 16 above the motor 20.

As illustrated in FIG. 2, a cover plate 184 is provided over top of the elongated tubes 98 which are disposed above the compressed air storage vessel 16. The cover 184 provides a guard against a user inadvertently contacting the elongated tubes 98. The cover 184 is mounted to the base 12 by threaded fasteners 186 as illustrated in FIG. 2. At the opposite end, the cover 184 is mounted to a projecting portion 190 of the crank case 24 as illustrated in FIG. 4. The projecting portion 190 includes a pair of threaded apertures 192 for receiving fasteners 194 (see FIG. 2) for securing the cover 184 to the crank case 24.

With reference to FIG. 15, the handle assembly 18 will now be described. The handle assembly 18 is mounted to the base 12 and includes first and second end support members 200. The end support members can have a generally U-shape and can be formed from circular tubing. Each end support 200 includes a pair of feet 202 which can be mounted to the base 12 utilizing threaded fastener 204 and nuts 206. In addition, a bumper 208 can be mounted to the bottom of the feet 202 to provide a cushion to the bottom of the air compressor 10. The end support members 200 each include an upper cross bar portion 210 that are provided with a pair of apertures 212 extending therethrough. Upper and lower handle members 214, 216, respectively can be sandwiched around the cross bar portion 210 and can receive threaded fasteners 218 therethrough to secure the handle portions 214, 216 to the end support members 200. Additional threaded fasteners 220 can be utilized for securing the upper handle portion 214 to the lower handle portion 216.

The handle assembly 18 can be utilized for lifting and moving the compressor 10 in a convenient manner so that the components of the compressor 10 do not have to be contacted by a user. The air compressor 10 of the present disclosure has a total weight no greater than 45 lbs and has a compact package having a height no greater than 12 inches, a length of no greater than 14 inches and a width of no greater than 10 inches. Thus, the entire air compressor can fit within a 14 inch cube which is far more compact than commercially available air compressors. It is noted that in a single piston compressor arrangement, the size and weight of the air compressor can be further reduced so that the weight of the air compressor can be less than 35 lbs. As illustrated in FIG. 1, the air compressor 10 is provided with a power cable 230 having a cable quick connect 232 that can be utilized for connection to a vehicle battery or other power source such as a 12 volt vehicle battery 234 as illustrated in FIG. 16. The air compressor electronics as illustrated in FIG. 16 includes an on/off switch 152 which is in communication with the vehicle battery 234. The solenoid 154 provides a relay for connecting the battery source to the motor 20 when the on/off switch 152 is closed. A pressure switch 240 is provided for interrupting supply of current to the solenoid 154 when the pressure in the compressed air storage vessel 16 exceeds a pre-determined level. The pressure switch 240 is provided in communication with the compressed air storage vessel 16 so as to automatically turn off the air compressor when a pre-determined pressure level is reached within the compressed air storage vessel 16.

With the air compressor 10 of the present disclosure, the compact and lightweight arrangement of the components provide for easy portability of the air compressor 10 while the DC electric motor 20 provides greater versatility by allowing the compressor 10 to be utilized wherever there is a DC power source such as a work vehicle nearby. The air compressor 10 also provides unique cooling features including a combined storage vessel and cooling function in the intercooler storage vessel. The arrangement of the cooling fan 110 for cooling all components of the air compressor 10 also provides for greater efficiency. 

1. An air compressor, comprising: an electric motor including a drive shaft; a crank assembly connected to a first end of said drive shaft; a connecting rod attached to said crank assembly; a piston connected to said connecting rod; a cylinder assembly fixedly mounted relative to a first end of said electric motor and receiving said piston therein; a fan drivingly attached to a second end of said drive shaft; a shroud surrounding said fan for directing cooling air axially along said motor housing from said second end toward said first end; and an intercooler assembly connected to said cylinder assembly for receiving compressed air from said cylinder assembly.
 2. The air compressor according to claim 1, wherein said intercooler assembly includes a storage vessel and a plurality of cooling fins disposed on a surface of said storage vessel.
 3. The air compressor according to claim 1, wherein said intercooler assembly is disposed above said electric motor.
 4. The air compressor according to claim 1, wherein said intercooler assembly is connected to said cylinder assembly by a pipe attached to said cylinder assembly and extending a length of said intercooler assembly and attached to an end of said intercooler assembly furthest from said cylinder assembly.
 5. The air compressor according to claim 4, further comprising a cover plate covering said pipe.
 6. The air compressor according to claim 1, further comprising a base including a base wall and a plurality of sidewalls receiving said electric motor therein.
 7. The air compressor according to claim 6, further comprising a handle assembly mounted to said base.
 8. The air compressor according to claim 6, wherein said handle assembly includes a pair of end support members mounted to opposite ends of said base and a handle extending between said end support members.
 9. The air compressor according to claim 6, wherein said base includes a plurality of vent openings therein.
 10. The air compressor according to claim 1, wherein said motor is a DC electric motor.
 11. The air compressor according to claim 1, further comprising a crankcase attached to said first end of said electric motor, said cylinder assembly being mounted to said crankcase and said intercooler assembly being mounted to said crankcase.
 12. The air compressor according to claim 1, wherein said compressor has a height of no greater than 12 inches, a length of no greater than 14 inches and a width of no greater than 10 inches.
 13. The air compressor according to claim 1, wherein said compressor has a weight of no greater than 45 pounds.
 14. An air compressor, comprising: an electric motor including a drive shaft; a crank assembly connected to a first end of said drive shaft; a connecting rod attached to said crank assembly; a piston connected to said connecting rod; a cylinder assembly fixedly mounted relative to a first end of said electric motor and receiving said piston therein; and an intercooler assembly connected to said cylinder assembly for receiving compressed air from said cylinder assembly, said intercooler assembly including a storage vessel and a plurality of cooling fins disposed on a surface of said storage vessel.
 15. The air compressor according to claim 14, wherein said intercooler assembly is disposed above said electric motor.
 16. The air compressor according to claim 14, wherein said intercooler assembly is connected to said cylinder assembly by a pipe attached to said cylinder assembly and extending a length of said intercooler assembly and attached to an end of said intercooler assembly furthest from said cylinder assembly.
 17. The air compressor according to claim 16, further comprising a cover plate covering said pipe.
 18. An air compressor, comprising: an electric motor including a drive shaft; a crank assembly connected to a first end of said drive shaft; a connecting rod attached to said crank assembly; a piston connected to said connecting rod; a cylinder assembly fixedly mounted relative to a first end of said electric motor and receiving said piston therein; a storage vessel connected to said cylinder assembly for receiving compressed air from said cylinder assembly; and a base including a base wall and a plurality of sidewalls receiving said electric motor therein.
 19. The air compressor according to claim 18, further comprising a handle assembly mounted to said base.
 20. The air compressor according to claim 19, wherein said handle assembly includes a pair of end support members mounted to opposite ends of said base and a handle extending between said end support members.
 21. The air compressor according to claim 18, wherein said base includes a plurality of vent openings therein.
 22. An air compressor, comprising: an electric motor including a drive shaft; a crank assembly connected to a first end of said drive shaft; a connecting rod attached to said crank assembly; a piston connected to said connecting rod; a cylinder assembly fixedly mounted relative to a first end of said electric motor and receiving said piston therein; a vessel connected to said cylinder assembly for receiving compressed air from said cylinder assembly, wherein said compressor has a height of no greater than 12 inches, a length of no greater than 14 inches and a width of no greater than 10 inches.
 23. The air compressor according to claim 22, wherein said compressor has a weight of no greater than 45 pounds.
 24. The air compressor according to claim 22, wherein said electric motor is a DC electric motor.
 25. The air compressor according to claim 23, further comprising a base for receiving said electric motor and a handle mounted to said base. 